Refractory furnace wall of a glass sheet floating tank

ABSTRACT

A refractory furnace wall has a refractory member spaced from the inner side of a wall member so as to define an intermediate space therebetween. The wall and refractory members are interconnected by a connector member which maintains the members in spaced relationship and which may be adjusted to vary the distance between the wall and refractory members.

United States Patent Brichard Mar. 28, 1972 [s41 REFRACTORY FURNACE WALL OF A 3,250,061 5/1966 Brotzmann ..65/182 0 GLASS SHEET FLOATING TANK 3,334,983 8/1967 Badger et al. ..65/182 R [72] Inventor: Edgard Blichard, Jumet, Belgium OTHER PUBLICATIONS [73] Assignee: Glaverbel, Watermael-Boitsfort, Belgium Progress Report on' Carbon Linings for Blast Furnaces by V. J. Nolan, Reprint from Blast Furnaces and Steel Plant, [221 1969 Apr. 1947 issue, pages 454 I0 460, T.S. 300.86 21 Appl. NO.Z 872,317

Primary Examiner-Arthur D. Kellogg Attorney-Edmund M. Jackiewicz [30] Foreign Application Priority Data 0m. 30, 1968 Luxembourg ..s7195 [571 ABSTRACT A refractory furnace wall has a refractory member spaced [52] US. Cl. "65/182 R, 65/356, 65/374, from the inner side ofa wall member so as to define an inter- 263/43, 2 1 66/43 mediate space therebetween. The wall and refractory mem- [51 Int. Cl. ..C03b 18/02 berg are interconnected by a connector member which main- Field of Search 1821, tains the members in spaced relationship and which may be 65/99 A; 263/46, 48; 266/43; 110/14 adjusted to vary the distance between the wall and refractory members. [56] References Cited 12 Claims, 15 Drawing Figures UNITED STATES PATENTS Frisch et al. ..263/46 PATENTEL mama 3,652,251

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INVENTOR EDGARD BRICHARD ATTORNEY REFRACTORY FURNACE WALL OF A GLASS SHEET FLOATING TANK The present invention relates to a refractory furnace of the type used in the production or treatment of flat glass floating on a liquid bath contained in the furnace, more particularly, to the construction of the refractory furnace wall. 1

In order to obtain the most effective utilization of heat in in dustrial furnaces it is necessary to minimize heat losses from the enclosed part of the furnace to the surrounding atmosphere. The use of normal refractory ceramic bricks for the furnace walls has been generally satisfactory in reducing heat losses since this material has the advantage of good mechanical behavior at high temperatures and good thermal insulation because of its relatively low coefficient of thermal conductivity. Heat losses by conduction from the interior of the furnace to the surrounding atmosphere are thus kept quite low.

While generally satisfactory, this known furnace lining has several disadvantages. One disadvantage results from the nonuniform nature of the convection currents outside of the enclosed furnace chamber. The convection currents flowing along the outer surface of the bottom of the furnace are relatively insignificant because their upward movement is blocked by the furnace bottom wall. However, the convection currents flowing along the outer surfaces of the side walls of the furnace may have relatively high speeds. The surrounding atmosphere in contact with the side walls is thus reheated to move upwardly along the walls and this upward movement draws in the cooler unheated atmosphere which in turn cools the side walls. The same cooling action occurs along the furnace crown whose curvature may be substantial. The external temperature gradients which are thus formed along the outer surfaces of the furnace walls are inevitably transmitted to the interior of the enclosed furnace chamber and result in internal temperature gradients which may reduce locally the temperature of the furnace contents. These localized reductions in temperature may have an extremely adverse effect on the proper operation of the furnace.

Internal temperature gradients may also occur as a result of specific thermal conditions within the furnace. In one such example the temperatures are higher in those areas of the furnace where the flames are produced by the burners. The resulting temperature gradients are transmitted to the contents within the furnace and produce internal convection currents which have an adverse effect on the homogeneity of the furnace contents. Since the refractory bricks have a low coefficient of thermal conduction in order to insulate properly the furnace interior of these temperature gradients. It has been proposed to counteract these temperature gradients by installing within the furnace a thermal conditioning system which is generally quite bulky and complex and is not always effective in minimizing the temperature gradients.

The existence of these temperatures gradients is extremely critical in refractory furnaces used for the production of float glass in float tanks since temperature differences are produced over the width of the bath and thus across the glass ribbon floating on the bath. These temperature differences over the width of the glass ribbon may cause differences in the thickness of the ribbon. These thickness variations will significantly affect the quality of the finished product.

Another disadvantage of the known refractory wall structure occurs when the refractory blocks are exposed to corrosive substances. Problems may occur since the refractory blocks having the highest resistance to corrosion do not necessarily possess the required thermal characteristics.

Another disadvantage of a refractory brick furnace wall exists when the refractory bricks support a liquid bath and the density of the bath liquid is greater than the density of the refractory blocks. Should the bath liquid flow between the joints separating the refractory bricks, the bricks may then be lifted by this liquid. The bricks may become detached and float to the surface of the bath. These floating bricks have an extremely adverse effect on the behavior of the furnace and the quality of the produced flat glass. The detached and floating refractory bricks are particularly critical in a float tank containing a bath liquid consisting of molten tin or metal salts which may lift the refractory bricks from their position on a metal base. The metal base is then attacked by the bath liquid and the glass ribbon floating on the bath is seriously damaged by the refractory bricks floating on the surface of the bath.

It is therefore the principal object of the present invention to provide a novel and improved refractory furnace wall.

It is another object of the present invention to provide a refractory furnace wall wherein a refractory member is spaced inwardly from a wall member by an adjustable connector.

It is an additional object of the present invention to provide a refractory furnace wall wherein the coeflicients of thermal conduction can be very simply and flexibly adapted in different directions.

It is a further object of the present invention to provide a refractory furnace wall having greater simplicity and flexibility of construction and at the same time is able to meet more effectively various and generally contradictory conditions.

According to one aspect of the present invention a refractory furnace wall may comprise a wall member and a refractory member on the side of the wall member toward the interior of the furnace. The refractory member is spaced from the wall member so as to define an intermediate space therebetween. A connector member interconnects the wall member and the refractory member through the intermediate space to maintain these members in a predetermined spaced relationship. The connector may comprise three parts assembled in axial extension of one another with one part being connected to the refractory member and another part being connected to the wall member. A third part between the two connecting parts is adjustable so as to vary the distance between the refractory and wall members. A layer of insulating material may be placed within the intermediate space. Thermal conditioning means may be positioned within the intermediate space or imbedded in high thermal conductivity means which is in the intermediate space.

The refractory furnace wall disclosed as the present invention has the advantage that the value of the coefficients of thermal conduction can be flexibly adapted in different directions. The intermediate space and the outer wall member enable conduction to the exterior of the furnace, and thus heat losses, to be controlled. The same intermediate space and the refractory members allow heat conduction to be controlled in a direction parallel to the furnace wall. The present invention is not limited to those elements which show one or more differences in heat conduction in different directions.

The refractory member is maintained at a predetermined distance from the wall member by a number of connectors which are spaced between these members. Thus, the refractory member which may be in contact with the contents of the furnace is anchored directly to the outer wall of the furnace by the connectors. This enables layers of different materials to be positioned between the wall member and refractory member without requiring the inner refractory member to be secured to the outer wall by means of these intermediate layers. Since the refractory member is anchored directly to the outer wall by the connector the likelihood of any lifting of the refractory members is eliminated. This is a particularly important advantage when a bath of molten material may exert a lifting force on the refractory element such as may occur in a float tank. Further, since the refractory member is anchored directly to the outer wall member there is no necessity for anchoring the intermediate members or materials positioned in the intermediate space. The materials in the intermediate space may be of metal or of refractory material.

Other objects and advantages of the present invention will be apparent upon reference to the accompanying description when taken in conjunction with the following drawings, which are exemplary, wherein;

FIG. 1 is a longitudinal vertical sectional view of a float tank to which the present invention may be applied;

FIG. 2 is a transverse vertical sectional view in enlarged scale of the bottom wall of the float tank and taken along the line II-ll of FIG. 3;

FIG. 3 is a partial top plan view of the bottom wall viewed in the direction of the arrow III of FIG. 2;

FIG. 4 is a vertical sectional view showing a connector member according to the present invention and taken along the line lV-IV ofFIG. 5;

FIG. 5 is a partial top plan view of another form of furnace wall embodying the present invention;

FIGS. 6 and 7 are views similar to FIGS. 4 and 5, respectively, of another embodiment of the present invention;

FIG. 8 is a vertical sectional view taken through a bottom wall and showing another form of connector member according to the present invention;

FIG. 9 is a sectional view taken along the line IX-IX of FIG. 8;

FIGS. 10 and 11 are views similar to that of FIG. 8 and showing other modifications of the present invention;

FIG. 12 is a vertical sectional view taken along the line XII-XII of FIG. 13 and showing another form of connector member;

FIG. 13 is a partial top plan view of a furnace wall embodying the connector of FIG. 12;

FIG. 14 is a vertical sectional view taken along the line XIV-XIV of FIG. 15 and showing still another form of connector member; and

. FIG. 15 is a partial top plan view of a furnace bottom wall incorporating the connector of FIG. 14.

Proceeding next to the drawings wherein like reference symbols indicate the same parts throughout the various views a specific embodiment and several modifications of the present invention will be described in detail.

In FIG. 1 there is illustrated diagrammatically a float glass apparatus comprising a tank furnace l, a float tank 2 and an annealing lehr 3. The float tank 2 comprises a bottom 4, a crown 5, side walls 6 and end walls 7,8. The end walls 7,8 are separated from the crown 5 by slots 9,10, respectively. These described components of the float tank are made of refractory materials. A metal wall or covering 11 hermetically seals the bottom 4, the side walls 6 and end walls 7,8 of the tank which contains a bath 12 of molten material. The tank furnace 1 contains a bath of molten glass 13 which flows over a lip 14 between casting rollers 15,16 which form a ribbon of glass 17. The glass ribbon is transported on rollers 18 through the slot 9 into the float tank and is deposited on the bath of molten material 12 to move thereon in the direction of the arrow X. The advancing glass ribbon 17 receives a fire polish on the bath of molten material 12 and progresses toward the slot 10 of the float tank where it is fed by rollers 19 to the annealing lehr 3.

The molten bath 12 in the float tank may comprise a molten metal salt or a molten metal, such as silver or tin.

Proceeding next to FIGS. 2 and 3 there is illustrated a refractory furnace wall according to the present invention as may be used in the float tank of FIG. 1. The wall as shown in FIG. 2 shows a bottom outer wall member 25 and a side wall member 26 which form an outer tightly sealed casing. The outer wall generally consists of sheet metal to provide stability of the furnace structure but may be also be formed from other materials of a suitable rigidity and may even comprise one or more refractory bricks or the like.

The refractory member comprises hexagonal refractory blocks 40-46 of graphite arranged contiguously as shown in FIG. 3 and separated from the bottom wall member 25 by an intermediate space 29. The side block 44 has a thickened portion 48 to provide a lateral wall for a recess defined in the interior of the tank and containing a bath 49 of molten tin upon which a glass ribbon 50 moves in a direction perpendicular to the plane of FIG. 2. Thus the tin bath 49 is positioned on the graphite slabs. A refractory brick 51 is positioned between the outer graphite slab 48 and the side wall 26 in order to insulate the side wall from the heat of the bath 49. The refractory members 40-46 are substantially parallel to the bottom outer wall 25 and are spaced therefrom in a direction toward the interior of the furnace. The refractory bricks may be in the form of plates or slabs having a polygonal shape such as rectangular or hexagonal. A regular polygonal or rectangular shape is most frequently used in order to facilitate the positioning of the refractory members however, they may also have a more complex shape so as to fit into given spaces. Generally, the thickness of refractory members is less than their other two dimensions but may be equal to or greater than these dimen- 810115- A connector member generally indicated at 52 is positioned at a junction of three adjacent slabs and anchors these slabs to the bottom wall 25. The connector member comprises a cylindrical part 55, a tubular part 56 and an end part 57. The cylindrical part 55 is provided at its upper end with a pair of spaced annular shoulders 59 and 60 which are used to anchor or interlock the connector member with the graphite slabs. The graphite slabs rest on the upper face of lower shoulder 59 and at the same time are wedged by the bottom face of the top shoulder 60. To accommodate the connector, the comers of these slabs are each provided with a recess so that three adjoining slabs form an opening 61 for the passage of the cylindrical part 55. The lower end of cylindrical part 55 is provided with external threads 63 and is threaded in corresponding internal threads 64 in the tubular part 56. The lower end of the bore of tubular part 56 is smooth.

The end part 57 comprises a foot,66 welded at 67 tothe bottom wall 25 and a swivel joint 68 on the top of the foot. Swivel joint 68 comprises a sphere whose diameter is substantially equal to the inner diameter of the bore of the tubular part 56. The swivel joint 68 engages the lower end of the tubular part 56. A pin 70 connects tubular part 56 and end part 57 and is inserted through passage 69 extending through both of these parts. The passage has sufficient clearance to provide for angular movement of the tubular part 56 with respect to the end part 57 in any direction. The axis of pin 70 isin a horizontal plane slightly below the horizontal great circle of the joint 68. The lower portion of the swivel joint 68 bears against an internal shoulder 71 formed within the end of the tubular part 56.

The upper end of the cylindrical part 55 is provided with a recess 54 which may be of hexagonal shape to receive a suitable tool in order to rotate the cylindrical part so as to raise or lower this part with respect to the tubular part 56. The three connector parts 55, 56 and 57 may be made from materials which can withstand the temperatures to which they are exposed during operation of the furnace. These parts may be made of metal, ceramic materials or graphite. The cylindrical part 55, or at least its head end, must comprise a material which is not attacked by the molten tin bath 49.

It is apparent that the connector member as described above provides for adjustment of the distance between the wall and refractory members so that precision of construction might be obtained with standard elements which have not been finely adjusted. The distances between the wall and refractory members may be adjusted to different amounts in different parts of the furnace. The present connector is adjustable after construction of the furnace and thus allows correction of the distance between the wall and refractory members after the furnace has been assembled. These corrections will compensate for deformations of the element due to thermal or other stresses.

The adjusting structure of the connector may be accessible for adjustment through the intermediate space, from the interior of the furnace or from outside of the furnace. When accessible from the exterior of the furnace, the intermediate space may be adjusted during the operation of the furnace. In addition the adjustment means are protected from high temperatures because it is at a distance from the inner surface of the furnace. When accessible from the interior of the furnace, final corrections in the furnace wall may be made after assembly of the furnace wall since the operator can see exactly what adjustments are required.

The connection between a connector member and the refractory member may be made completely on the side of the refractory member away from the furnace interior so that the inner surface of the refractory member is free from any bumps or projections which might form a snag or obstacle to the materials in the furnace.

The intermediate space 29 between the graphite slabs 40-46 supported by the connector members 52 and the wall member 25 contains threee refractory layers 30-32 of insulating materials. Layer 32 consists of a graphite powder which facilitates heat transfer between the tin bath 49 and the conduits 35 and 36 in which flows a thermal conditioning fluid. Layer 31 consists of Kieselguhr powders and layer 30 consists of mineral wool. These compositions of the layers are only illustrative examples and any of the layers may have any suitable composition to enable the layer to withstand the heat temperature encountered at that particular area in the intermediate space. As many refractory layers may be provided as are considered necessary to withstand the local temperatures. For temperatures above 1,750 C. powders having a high alumina content will be used, for example, an alumina content of at least 45 percent. At about 1,750 C. Kaolin-based powders containing 43 percent of alumina will be used and below l,000 C. asbestos powders will be used.

The refractory layers as described above may occupy only a portion of the intermediate space and these layers may be made from materials other than powders such as, for example, fibers, nodules, pebbles, expanded materials or blocks of a particular density. A binder may be added to the pulverulent elements. The proportion of binder should be small enough not to clog the pores between the granules but sufficient to lightly bond the granules together so as to form a coherent although slightly friable or loosely packed mass. The binder may be one that hardens only on use and not when the lining is being put into position. Examples of such binders are ceramic binders, hydraulic cements, sodium silicate, solutions of molasses or sugar, tars or asphalts, or heavy hydrocarbons. The layers 30-32 are turned upwardly against the side wall 26 as may be seen in FIG. 2. The porosity of the materials within the intermediate space should be such to permit the passage of any evolved gases. These gases are removed through a plurality of orifices 73 appropriately arranged in the wall 25 and connected to ducts 74.

The use of insulating materials in the intermediate space reduces the heat losses and provides greater flexibility insuring proper insulation of the furnace. An insulating material in powder form provides good insulation and facilitates filling spaces of complex shapes. Insulating material may also be in pebble form and the pebbles may be porous. Space occupied by the pebbles contains a considerable amount of air and these air spaces together with the insulating material provides the insulating effect. When insulating material in fiber form is used the fibers will enclose a considerable amount of air and will allow considerably greater reduction depending upon their orientation and particularly if the fibers are of carbon. The insulating material may also be formed from refractory ceramic bricks when working conditions within the furnace so require. This would be the case when the furnace must support heavy loads.

In constructing the refractory furnace wall according to the present invention the connecting members 52 are first fitted onto the bottom wall 25. The foot end of part 57 is inserted through the tubular part 56.and then welded at 67 to the bottom wall 25. Cylindrical part 55 is then threaded into the upper end of tubular part 56. As the graphite slabs are being fitted together the upper ends of the cylindrical part 55 are inserted at their junctions. The refractory lining is thus formed progressively. Each slab is successively positioned on some of the connectors associated with it with the additional connectors being positioned after each placing of the graphite slabs. Any space between the upper end of the connector and the inner surface of the refractory member may be filled with any appropriate cement in order to eliminate any cavities or depressions in the inner surface of the wall and this surface will then be smooth.

During the assembly of the refractory wall or after the assembly has been completed the distance between the graphite slabs and the bottom wall 25 can be adjusted by rotating the cylindrical member 55 in the tubular member 56 by means of the recess 54 into which a suitable tool has been inserted. The insulating materials are then introduced into the intermediate space either during or after the assembly of the refractory wall. The thermal conditioning conduits 35,36 are next inserted into the intermediate space.

The thermal conditioning system including the conduits 35 and 36 may be positioned in the intermediate space in order to replace some of the conventional conditioning structures mounted in the furnace chamber and which give rise to problems in connection with the space occupied and the effective operation of the furnace. The thermal conditioning means may comprise conduits for a flow of liquid, electrical resistors or any other suitable means. The thermal conditioning means may be imbedded in a material having a high thermal conductivity and separated from the contents of the furnace substantially only by layers having a thermal conductivity. This arrangement greatly intensifies the effect of the thermal conditioning. The material of high thermal conductivity causes the heat to be rapidly and intensively propagated from the zone of the furnace which is being conditioned to the conditioning means or in the opposite direction depending upon whether the conditioning is intended to have a cooling or heating effect. The high thermal conductivity material may be a liquid metal since it does have the advantage of perfectly filling available spaces.

Complete filling of the intermediate space has the advantage of providing additional support for the refractory members and thus the size of the connector members can be reduced. In addition, this arrangement reduces the possibility of the liquid contained in the furnace from escaping into the intermediate space.

At least a portion of the materials in the intermediate space may be impermeable to the liquid which is to come into contact with the furnace wall. This eliminates the necessity of filling in the joints between the refractory members and also lessens the risk of an insulation loss of the loss of any liquid which may settle in the intermediate space. At least a part of the materials in the intermediate space has a wetting angle relative to the liquid such that the latter cannot penetrate into the paths between these materials. This avoids the difficulty of forming a tightly sealed layer. One of the layers may essentially consist of carbon. The good thermal conductivity properties of carbon enables the carbon layer to maintain a uniform temperature in a given direction. This production of a uniform temperature is particularly advantageous in a transverse direction of the furnace in order that the bath of molten material may be homogeneous over its entire width. This advantage is particularly useful in the bath of a float tanksincc temperature gradients in a transverse direction relative to the movement of the glass ribbon may produce harmful variations in thickness over the width of the ribbon.

The carbon layer also provides good heat transmission for the thennal conditioning system. Carbon is also a good refractory and withstands the effects of temperature. Carbon does not bubble and does not discharge gases or vitreous phases and is not likely to contaminate the surroundings.

It is preferred that the refractory element be formed at least partially from slabs consisting mainly of carbon. In addition to the above mentioned advantages the glass is prevented from sticking to the refractory furnace wall. Such an effect may be harmful in some furnaces. In a float tank the glass ribbon must be prevented from sticking to the refractory walls after any operational incident.

Another advantage of having carbon layer on the inner surface of the refractory member is the result of its reducing properties. Carbon readily absorbs oxygen and then liberates it primarily in the fonn of CO. The action of carbon is thus beneficial because a reducing atmosphere is generally necessary in furnaces in order to avoid as far as possible oxidation of furnace components such as conduits or supporting structures. Oxidation of the bath of molten material must also be frequently avoided particularly in float tanks. A high-carboncontent refractory member in contact with the molten bath protects the bath against oxidation and thus improves both its purity and its useful life.

The present invention also discloses other forms of refractory wall structures for a furnace. Several of these modifications are illustrated in subsequent drawings and for purposes of clarity the materials filling the intermediate space 29 have not been shown in the drawings.

in FIGS. 4 and a hexagonal refractory member 76 has a connector 75 secured integrally therewith at its center. The lower portion of the connector 75 passes through a refractory block 77 through a hole 78. The refractory block 77 together with additional refractory blocks 79 forms the bottom wall of the furnace with this wall being positioned on a support structure comprising support members 80. Nuts 81 and 82 are threaded onto a threaded portion 83 of the connector 75 and on both sides of the refractory block 77 to enable the connector 75 to be anchored in this bottom wall of the furnace. The adjustability of the nuts 81 and 82 also provides for varying the distance between the refractory member and the bottom wall.

It is pointed out that in the modifications of FIGS. 4-5 the connector comprises a foot portion which is integral with the refractory member so as to form a part thereof. This arrangement is particularly advantageous when the refractory member is relatively thin. Otherwise, such thin refractory members would not have sufficient thickness for anchoring the connector therein and thus would be susceptible to breaking. When the connector is provided with a foot portion integral with the refractory member, this critical point of the refractory member is reinforced and the stresses therein are significantly reduced. This arrangement is also highly resistant to the considerable stresses which may result from difficult temperature conditions. The tight seal of the refractory member is also improved since there are no openings through the refractory member to accommodate the connector. The connector foot may consist of the same material as the refractory member or of a different material which may have greater strength. The foot may be molded integrally with the refractory member or may be welded thereto.

According to the present invention at least one connector member is attached to a single refractory member. With a single connectorthe distance between the refractory member and the wall can be adjusted individually. The same adjustment is possible when a number of connectors are joined to the same refractory member and, in addition the refractory member may be inclined. These adjustments of the refractory members are possible even when the members are of varying thicknesses with respect to each other. By connecting a connector to two or more refractory members in the area of a juncture between these members the number of connectors required can be reduced.

Proceeding next to FIGS. 6 and 7, three connector members 91-93 are rigidly secured to a refractory member 90 with the heads 94 of the connectors being integral with the refractory member. The threaded ends 95 of the connectors engage in a base portion indicated generally at 96 and including a tubular part 97 which is internally threaded and has a hexagonal outer surface. The base portion 96 includes a cylindrical part 98, a shoulder 99 abutting the bottom wall 89 and a nipple 100 whose end is provided with a slot 101. The distance between the refractory member 90 and the bottom wall 89 is adjusted from within the intermediate space by using a suitable tool to rotate the tubular part 97 or by rotating the nipple '100 below the wall 89. A weld 102 both seals and anchors the nipple 100 to the bottom 89.

In FIGS. 8 and 9, a refractory member 105 is rigidly secured to a-connector 106 having a head or end portion 107 integral with the refractory member. The end of the connector 106 is received in a tubular part 109 of a base portion indicated generally at 108. A second part 110 of the base portion 108 has a threaded end 111 which is engaged in a correspondingly threaded hole 112 in the bottom wall 113. The extreme end of part 110 is hexagonal as indicated at 122. The part 106 has a smaller diameter portion 115 near its end which forms an annular recess 116 as shown in FIG. 9. A pair of parallel pins 117 each having a cross section substantially equal to that of the recess 116 are fitted into this recess with each pin passing through holes 118 and 119 formed in the tubular part 109. The pins 117 prevent vertical movement of the part 106 with respect to the tubular part 109 while allowing the tubular part to rotate around the part 106. The threaded end 111 anchors the connector in the wall 113 and at the same time permits adjustment of the distance between refractory member 104 and wall 113 by rotation of the part 110. Lock nut 120 is secured in position after the desired adjustment has been made.

In FIG. 10 a refractory member has a threaded bore 126 therethrough within which is received a threaded end 127 of a cylindrical member 128. The cylinder 128 has its other end 129 also fitted and this end engages in the internal threaded tubular part 130 of a base portion indicated generally at 131. The base portion 131 has a threaded end 132 which extends through a hole 136 formed in the wall member 135. Two pairs of nuts 137-140 anchor member 131 on the wall 135. To simplify the drawing these nuts have not been shown in cross section.

The surfaces of the nuts 138 and 139 adjacent to the partition is rounded so that clearance of the hole 136 permits angular movement of the entire arrangement including the refractory member 125 and the members 128 and 131 through an angle of several degrees in all directions. The entire system can then be locked in position by means of the nuts 137 and 140. Final adjustment of the distance between the refractory member and the wall may be carried out by means of a threaded end 127 of the member 128 and, more particularly, by means of a slot 142 formed in its head. For a first adjustment, the nuts 137-140 have been placed at an appropriate height on the base member 131.

After completion of the adjustments the nuts are clamped against both sides of the wall 135. A sealing-tight lug 144 is welded to the undersurface of the wall 135 at 145. Refractory cement 143 is placed in that portion of the threaded bore 126 of the refractory member 145 that is not filled by the threaded connector end 127.

In FIG. 11, there is shown a refractory member 145 having a threaded bore 156 to receive a threaded end 157 of a cylindrical member 158. The other end of the cylindrical member 158 is spherical at 159 with this spherical end being inserted in a tubular member 162 whose upper end 163 has an internal diameter less than the diameter of spherical part 159 but larger than that of cylindrical member 158. The bottom end of the tubular member 162 has the same internal diameter as the sphere 159 and is internally threaded to receive a headless screw 166 which prevents the spherical part 159 from dropping. The cylindrical member 158 is thus capable of rotation within the tubular member 168 and also of angular movement through several degrees.

A rod-like member 169 is welded to screw 166 at 168 and its bottom end 170 is provided with a sphere received in a tubular member 171 whose upper end has a diameter substantially equal to the diameter of the rod 169. The remaining portion of the tubular member 171 has a diameter equal to that of sphere 170. The bottom portion 173 of tubular member 171 has internal threads and receives a headless screw 174 which supports the spherical end 170. Tubular member 171 is welded to the wall 176 at 175. The distance between the refractory member and the wall 176 is first adjusted by means of the screw 174 through the opening 177 passing through the bottom wall 176. A second adjustment is carried out by the threaded part 157 of the cylindrical member 158.

In the wall structure illustrated in FIGS. 12 and 13 each connector member 189 functions to anchor two adjacent square refractory members 190. A connector is located at the center of the adjacent sides. At these locations the refractory members are provided with recesses so that two adjoining blocks define a passage aperture having a top part 191 which is rectangular and a bottom part 192 which is cylindrical. An upper threaded end 193 of a cylindrical member 194 is received within these recesses and anchors two refractory members 190 by nuts 196 and 197. The surfaces of the nuts 196 and 197 in contact with the refractory members are rounded to provide for angular movement of the cylindrical member 194 through an angle of several degrees. A perforated plate 199 having a configuration similar to the shape of the top recess 191 except for clearance exerts an anchoring pressure on the adjacent refractory blocks 199 by means of the top nut 196. Sufficient clearances are provided for the recess and for plate 199 to permit this angular movement of the cylindrical member 194.

The cylindrical member 194 has a spherical end 202 received in a tubular member 203 the upper end of which has a smaller diameter than the spherical end 202 but larger than the cylindrical member 194. This relationship allows both rotational and angular movement of the cylindrical member 194. The bottom portion 204 of the tubular member 203 has a diameter equal to that of the sphere 202 and is internally threaded to receive a headless screw 205 which prevents the cylinder 194 from sliding down through tubular member 203. The tubular member 203 is welded to a bottom wall 206 at 207. The distance between the wall 206 and the refractory member 190 is adjusted by means of nuts 196 and 197 and can also be accomplished by the headless screw 205 through an opening 208 and the bottom wall 206.

In FIGS. 14 and 15, a connector member 209 anchors four square refractory members 210 each of which are provided at their corners with a suitable recess 211 to enclose a spherical head 215 of a cylindrical member 216 so that the refractory members cannot move upwardly or downwardly with respect to the cylindrical member 216 as viewed in FIG. 14. The cylindrical member 216 has a threaded lower end 217 received in an internally threaded tubular member 218 while the bottom end of the tubular member receives a cylindrical member 219 anchored therein by a pin 220 passing through holes 221 and 222 in the members 218 and 219 respectively. Sufficient clearances are provided in these holes to allow the tubular member 218 a certain angular play with respect to the member 219 around the pin 220 and in a plane perpendicular thereto.

The bottom end of the cylindrical member 219 is secured between a pair of gussets 225 by a pin 226 extending through openings in these gussets. The cylindrical member 219 thus has an angular play with respect to the gussets in the plane of the drawing. The gussets 225 are welded to the bottom wall 228 at 227. The distance between the refractory members 210 and the wall 228 is adjusted by inserting a tool in a slot 230 formed in the spherical head 225 of the cylindrical member 216.

In any of the above described embodiments of the present invention the refractory furnace element may be provided with means through which powdered material can be added to the intermediate space. These means may comprise an opening normally closed by a tightly fitting plug so that extra powder can be introduced below the refractory members. The introduction of this powder enables the insulating properties of the intermediate space to be adjusted and also compensates for any reduction in the volume of the powder occurring during operation of the furnace.

The refractory member may also have at least one area where localized cooling is required. This may be accomplished by providing less insulating filling material in the intermediate space underlying this localized area. By using less insulating material it is possible to promote heat transfer from an area which is to be cooled.

Thus it can be seen that the present invention discloses a simple arrangement of components for constructing a refractory furnace wall which allows ready and rapid adaption to the conditions required for a specific treatment. Such conditions may be, for example, the use of insulating materials in order to limit heat losses, conductive materials to increase heat losses at some areas or to equalize temperature gradients, materials adapted to the contents of the furnace in order to prevent corrosion or sticking or in order to insure a reaction with the contents, and materials which can withstand the different temperatures encountered during the operation of such a refractory furnace. These conditions are not exhaustive but are merely illustrative and it would also be possible to use a wearresistant layer or layers to provide a seal with respect to a gas or liquid. These conditions may be achieved either separately or in combination by employing the combination of the wall member, the intermediate space, and the refractory member as disclosed herein.

It will be understood that this invention is susceptible to modification in order to adapt it to different usages and conditions.

What is claimed is:

1. A refractory furnace structure for the production or treatment of flat glass floating on a liquid bath contained therein, said furnace structure comprising a refractory member for contacting the liquid bath, a wall member spaced from said refractory member and defining an intermediate space therebetween, said space being filled with gas permeable, substanially non-supporting material and which withstands the temperature encountered during the glass floating operation, a connector member positioned within the refractory furnace and interconnecting said refractory member and wall member, said connector member extending through said intermediate material and filling insaid space, the connector being interlocked at its upper end with said refractory member and directly anchored to said wall member at it opposite end whereby lifting of the refractory member upwardly relative to the liquid bath and movement toward or away from said wall member is limited.

2. In a refractory furnace wall structure as claimed in claim 1 and comprising means on said connector member for adjusting the distance between said wall and refractory member.

3. In a refractory furnace wall structure as claimed in claim 1 wherein said connector member comprises a plurality of parts assembled in extension of one another.

4. In a refractory furnace wall structure as claimed in claim 3 and comprising means between two parts of said connector member for rotatably connecting said parts with respect to each other.

5. In a refractory furnace wall structure as claimed in claim 3 and comprising means between two parts of said connector member for movably connecting said parts so that one part is movable angularly with respect to an extension of the axis of the other part.

6. In a refractory furnace wall structure as claimed in claim I wherein said connector has an end portion rigidly secured to said refractory member.

7. In a refractory fumace wall structure as claimed in claim 1 wherein there are a plurality of refractory members defining at least one joint therebetween, said connector member being joined to said plurality of refractory members at said joint.

8. In a refractory furnace wall structure as claimed in claim 1 wherein said insulating material comprises a layer of noncoherent material, and a binder in said non-coherent material.

9. In a refractory furnace wall structure as claimed in claim 1 and comprising thermal conditioning means within said intermediate space.

10. In a refractory furnace wall structure as claimed in claim 9 and comprising high thermal conductivity means within said intermediate space, said thermal conditioning means being imbedded in said high thermal conductivity means, said refractory member having high thermal conductivity and said thermal conditioning means being separated from the furnace contents only by high thermal conductivity means. 

2. In a refractory furnace wall structure as claimed in claim 1 and comprising means on said connector member for adjusting the distance between said wall and refractory member.
 3. In a refractory furnace wall structure as claimed in claim 1 wherein said connector member comprises a plurality of parts assembled in extension of one another.
 4. In a refractory furnace wall structure as claimed in claim 3 and comprising means between two parts of said connector member for rotatably connecting said parts with respect to each other.
 5. In a refractory furnace wall structure as claimed in claim 3 and comprising means between two parts of said connector member for movably connecting said parts so that one part is movable angularly with respect to an extension of the axis of the other part.
 6. In a refractory furnace wall structure as claimed in claim 1 wherein said connector has an end portion rigidly secured to said refractory member.
 7. In a refractory furnace wall structure as claimed in claim 1 wherein there are a plurality of refractory members defining at least one joint therebetween, said connector member being joined to said plurality of refractory members at said joint.
 8. In a refractory furnace wall structure as claimed in claim 1 wherein said insulating material comprises a layer of non-coherent material, and a binder in said non-coherent material.
 9. In a refractory furnace wall structure as claimed in claim 1 and comprising thermal conditioning means within said intermediate space.
 10. In a refractory furnace wall structure as claimed in claim 9 and comprising high thermal conductivity means within said intermediate space, said thermal conditioning means being imbedded in said high thermal conductivity means, said refractory member having high thermal conductivity and said thermal conditioning means being separated from the furnace contents only by high thermal conductivity means.
 11. In a refractory furnace wall structure as claimed in claim 1 wherein said refractory member comprises a slab consisting essentially of carbon.
 12. A refractory furnace structure as defined in claim 1 wherein the intermediate space is filled with loosely packed gas permeable material. 